A gibbon living alone in her cage gave birth to a baby. Zookeepers finally know how – Orange County Register

By Xiaofei Xu, Philip Wang and Junko Ogura

Japanese zookeepers believe they have solved the mystery of how a gibbon got pregnant despite living alone in her cage.

Momo, a 12-year-old white-handed gibbon, shocked her keepers at Kujukushima Zoo and Botanical Garden in Nagasaki in February 2021 when she gave birth despite unknown male company.

Now, two years later, after a DNA test of their baby, the zoo has discovered who the father is – and even has a theory about how the gibbons mated.

The test revealed that the father was Itō, a 34-year-old agile gibbon who was staying in an adjacent pen owned by Momo around the time Momo became pregnant.

The zoo told CNN Friday it believes Momo and Itō managed to mate through a small hole in a steel plate between their enclosures. The hole was about 9 millimeters (0.3 inch) in diameter.

The baby monkey – whose name has yet to be named – now weighs about 2 kilograms (4.4 pounds) and is “growing healthy” under Momo’s loving attention, the zoo said.

“It is a precious life born into the world, we will continue to take good care of him and hope he will live a healthy long life,” said Hideki Hisano, deputy director of the zoo.

Gibbons are among the smallest of apes, but they have loud singing voices that have evolved into elaborate language and can swing from branch to branch at speeds of up to 35 miles per hour.

There are dozens of gibbon species native to parts of Asia, from northeastern India to China to the Borneo archipelago.

The population of agile gibbons in the wild has been declining and they have been listed as a vulnerable species in the International Union for Conservation of Nature due to their habitat being threatened by human activities such as logging, mining and road construction.